scholarly journals A Geometallurgical Approach to Tailings Management: An Example from the Savage River Fe-Ore Mine, Western Tasmania

Minerals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 454 ◽  
Author(s):  
Anita Parbhakar-Fox ◽  
John Glen ◽  
Bonita Raimondo
Keyword(s):  
Mine Waste ◽  
Mineral Chemistry ◽  
Cobalt Hydroxide ◽  
Tailings Dam ◽  
Total Oxidation ◽  
Controlling Parameter ◽  
Tailings Management ◽  
Pyrite Concentrate ◽  
High Concentrations ◽  
Co Precipitation

At the Old Tailings Dam (OTD), Savage River, Western Tasmania, 38 Mt of pyritic tailings were deposited (1967 to 1982) and have since been generating acid and metalliferous drainage (AMD). Mineral chemistry analysis confirmed high concentrations of refractory cobalt in pyrite (up to 3 wt %). This study sought to determine, through a series of bench scale tests, if Co could be liberated using biohydrometallurgical techniques. Four bulk tailings samples were collected across the OTD, from up to 1.5 m depth, targeting three sulphide-bearing facies. The study was conducted in four stages: (1) bacterial adaption using BIOX® bacteria; (2) biooxidation optimization with pH, temperature and Fe medium parameters tested; (3) flotation test work to produce a sulphide concentrate followed by biooxidation; and (4) Fe and Co precipitation tests. The BIOX® culture adapted to the bulk composite (containing 7 wt % pyrite) in ~10 days, with biooxidation occurring most efficiently at pH 1.5–1.6 and 40 °C whilst the Fe medium concentration was identified as a less-controlling parameter. Flotation produced a 71% pyrite concentrate with total oxidation occurring after 14 days of biooxidation with 99% of Co leached. At pH 3, Co was effectively separated from Fe, however Ni and Cu were also present in the pregnant liquor solution and therefore required refining before production of cobalt hydroxide, the intermediate saleable product. This study shows that adopting a geometallurgical approach to tailings characterisation can identify if mine waste has commodity potential and how best to extract it therefore unlocking the potential for unconventional rehabilitation of AMD affected sites.

scholarly journals Geochemistry, Mineralogy and Microbiology of Cobalt in Mining-Affected Environments

Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 22
Author(s):  
Gabriel Ziwa ◽  
Rich Crane ◽  
Karen A. Hudson-Edwards
Keyword(s):  
Mine Waste ◽  
Modern Technology ◽  
Ore Deposits ◽  
Raw Material ◽  
Knowledge Gaps ◽  
Mining Operations ◽  
Environmental Transformation ◽  
Ph Conditions ◽  
High Concentrations ◽  
Co Precipitation

Cobalt is recognised by the European Commission as a “Critical Raw Material” due to its irreplaceable functionality in many types of modern technology, combined with its current high-risk status associated with its supply. Despite such importance, there remain major knowledge gaps with regard to the geochemistry, mineralogy, and microbiology of cobalt-bearing environments, particularly those associated with ore deposits and subsequent mining operations. In such environments, high concentrations of Co (up to 34,400 mg/L in mine water, 14,165 mg/kg in tailings, 21,134 mg/kg in soils, and 18,434 mg/kg in stream sediments) have been documented. Co is contained in ore and mine waste in a wide variety of primary (e.g., cobaltite, carrolite, and erythrite) and secondary (e.g., erythrite, heterogenite) minerals. When exposed to low pH conditions, a number of such minerals are known to undergo dissolution, typically forming Co2+(aq). At circumneutral pH, such aqueous Co can then become immobilised by co-precipitation and/or sorption onto Fe and Mn(oxyhydr)oxides. This paper brings together contemporary knowledge on such Co cycling across different mining environments. Further research is required to gain a truly robust understanding of the Co-system in mining-affected environments. Key knowledge gaps include the mechanics and kinetics of secondary Co-bearing mineral environmental transformation, the extent at which such environmental cycling is facilitated by microbial activity, the nature of Co speciation across different Eh-pH conditions, and the environmental and human toxicity of Co.

Total oxidation of propane over Cu-Mn mixed oxide catalysts prepared by co-precipitation method

2011 ◽  
Vol 28 (4) ◽  
pp. 1139-1143 ◽  
Author(s):  
Moon Hyeon Kim ◽  
Kyung Ho Cho ◽  
Chae-Ho Shin ◽  
Seong-Eun Kang ◽  
Sung-Won Ham
Keyword(s):  
Mixed Oxide ◽  
Oxide Catalysts ◽  
Precipitation Method ◽  
Total Oxidation ◽  
Mixed Oxide Catalysts ◽  
Co Precipitation

scholarly journals From Bench-Scale to Prototype: Case Study on a Nickel Hydroxide—Activated Carbon Hybrid Energy Storage Device

Batteries ◽  
2019 ◽  
Vol 5 (4) ◽  
pp. 65
Author(s):  
Alberto Adan-Mas ◽  
Pablo Arévalo-Cid ◽  
Teresa Moura e Silva ◽  
João Crespo ◽  
Maria de Fatima Montemor
Keyword(s):  
Activated Carbon ◽  
High Energy ◽  
High Energy Density ◽  
Storage Device ◽  
Cobalt Hydroxide ◽  
Bench Scale ◽  
Geometrical Constraints ◽  
Co Precipitation ◽  
Hybrid Devices

Hybrid capacitors have been developed to bridge the gap between batteries and ultracapacitors. These devices combine a capacitive electrode and a battery-like material to achieve high energy-density high power-density devices with good cycling stability. In the quest of improved electrochemical responses, several hybrid devices have been proposed. However, they are usually limited to bench-scale prototypes that would likely face severe challenges during a scaling up process. The present case study reports the production of a hybrid prototype consisting of commercial activated carbon and nickel-cobalt hydroxide, obtained by chemical co-precipitation, separated by means of polyolefin-based paper. Developed to power a 12 W LED light, these materials were assembled and characterized in a coin-cell configuration and stacked to increase device voltage. All the processes have been adapted and constrained to scalable conditions to ensure reliable production of a pre-commercial device. Important challenges and limitations of this process, from geometrical constraints to increased resistance, are reported alongside their impact and optimization on the final performance, stability, and metrics of the assembled prototype.

Study on Sn-Fe-Cr Composite Oxides: Novel, Active and Thermally Stable Catalysts for CH4 Total Oxidation

2002 ◽  
Vol 216 (7) ◽  
Author(s):  
X. Wang ◽  
Y. Xie
Keyword(s):  
Thermal Stability ◽  
Metal Oxide ◽  
Specific Surface ◽  
Redox Reaction ◽  
Metal Oxide Catalysts ◽  
Total Oxidation ◽  
Surface Areas ◽  
Composite Oxides ◽  
Specific Surface Areas ◽  
Co Precipitation

With the combination of redox reaction and co-precipitation, a series of Sn-Fe-Cr composite metal oxide catalysts with various compositions were prepared, which exhibit higher specific surface areas, thermal stability and CH

scholarly journals Effect of Y Modified Ceria Support in Mono and Bimetallic Pd–Au Catalysts for Complete Benzene Oxidation

Catalysts ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 283 ◽  
Author(s):  
Lyuba Ilieva ◽  
Anna Venezia ◽  
Petya Petrova ◽  
Giuseppe Pantaleo ◽  
Leonarda Liotta ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Benzene Oxidation ◽  
Total Oxidation ◽  
Pd Catalysts ◽  
X Ray ◽  
Close Relationship ◽  
Ceria Support ◽  
Co Precipitation

Mono metallic and bimetallic Pd (1 wt. %)–Au (3 wt. %) catalysts were prepared using two ceria supports doped with 1 wt. % Y2O3. Yttrium was added by impregnation or co-precipitation. The catalyst synthesis was carried out by deposition–precipitation method, with sequential deposition–precipitation of palladium over previously loaded gold in the case of the bimetallic samples. The obtained materials, characterized by X-ray powder diffraction (XRD), High resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and temperature programmed reduction (TPR) techniques, were tested in the complete benzene oxidation (CBO). The results of the characterization analyses and the catalytic performance pointed to a close relationship between structural, redox, and catalytic properties of mono and bimetallic catalysts. Among the monometallic systems, Pd catalysts were more active as compared to the corresponding Au catalysts. The bimetallic systems exhibited the best combustion activity. In particular, over Pd–Au supported on Y-impregnated ceria, 100% of benzene conversion towards total oxidation at the temperature of 150 °C was obtained. Comparison of surface sensitive XPS results of fresh and spent catalysts ascertained the redox character of the reaction.

Emergency remediation of instability at Caudalosa tailings dam, Peru: a case history

2002 ◽  
Vol 39 (5) ◽  
pp. 1193-1200 ◽  
Author(s):  
Vinod K Garga ◽  
Miguel de la Torre
Keyword(s):  
Case History ◽  
Large Deformations ◽  
Mine Waste ◽  
Waste Rock ◽  
Tailings Dam ◽  
Plastic Clay ◽  
Mine Waste Rock ◽  
Emergency Stabilization ◽  
Subsurface Investigations ◽  
Visual Observations

This paper describes the instability in the foundation of the Caudalosa tailings dam in Peru. The instability threatened collapse of the structure along with the risk of unacceptable contamination of the River Escalera, located immediately downstream of the toe of the dam. At the time of these investigations, large deformations were in progress. The head scarp of the potential slide, located in the stored tailings, had reached a height of 2 m. Visual observations, as well as subsurface investigations, indicated that the instability was due to the presence of soft to medium plastic clay in the foundation. Emergency stabilization was successfully achieved by the construction of large trenches at the downstream toe, allowing the low consistency clay to be removed and backfilled with compacted mine waste rock. Other secondary stabilizing measures that were undertaken are also described.Key words: clay, dam, instability, remediation, stabilization, slide, tailings.

scholarly journals Hydrogeochemical Behavior of Reclaimed Highly Reactive Tailings, Part 1: Characterization of Reclamation Materials

Minerals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 596 ◽  
Author(s):  
Alex Kalonji-Kabambi ◽  
Bruno Bussière ◽  
Isabelle Demers
Keyword(s):  
Acid Mine Drainage ◽  
Mine Drainage ◽  
Mine Waste ◽  
Mining Industry ◽  
Companion Paper ◽  
Mine Wastes ◽  
Acid Mine ◽  
High Concentrations ◽  
Neutralizing Potential ◽  
Sulfide Tailings

The production of solid mine wastes is an integral part of the extraction and metallurgical processing of ores. The reclamation of highly reactive mine waste, with low neutralizing potential, is still a significant challenge for the mining industry, particularly when natural soils are not available close to the site. Some solid mine wastes present interesting hydro-geotechnical properties which can be taken advantage of, particularly for being used in reclamation covers to control acid mine drainage. The main objective of this research was to evaluate the use of mining materials (i.e., tailings and waste rock) in a cover with capillary barrier effects (CCBE) to prevent acid mine drainage (AMD) from highly reactive tailings. The first part of the project reproduced in this article involves context and laboratory validation of mining materials as suitable for a CCBE, while the companion paper reports laboratory and field results of cover systems made with mining materials. The main conclusions of the Part 1 of this study were that the materials studied (low sulfide tailings and waste rocks) had the appropriate geochemical and hydrogeological properties for use as cover materials in a CCBE. Results also showed that the cover mining materials are not acid-generating and that the LaRonde tailings are highly reactive with pH close to 2, with high concentrations of metals and sulfates.

scholarly journals Photocatalytic degradation of reactive black 5 on the surface of tin oxide microrods

2018 ◽  
Vol 16 (5) ◽  
pp. 773-781 ◽  
Author(s):  
Shanza Rauf Khan ◽  
Muhammad Umar Khalid ◽  
Saba Jamil ◽  
Songnan Li ◽  
Aiman Mujahid ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Tin Oxide ◽  
Degradation Kinetics ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Reactive Black 5 ◽  
Unit Cells ◽  
High Concentrations ◽  
Co Precipitation ◽  
Kinetics Of

Abstract A simple co-precipitation technique is proposed for synthesis of tin oxide (SnO2) microrods. Stannous chloride and urea were used during synthesis. X-ray powder diffraction (XRD) analysis revealed that the annealed product consists of SnO2 microrods having tetragonal unit cells, while scanning electron microscopy (SEM) analysis revealed the rod-like morphology of a synthesized product. These synthesized microrods are used as photocatalyst for the degradation of reactive black 5 (RB5). Degradation kinetics of RB5 are monitored under daylight in different concentrations of hydrogen peroxide (H2O2) and catalyst. The percentage of RB5 conversion is also calculated at various concentrations of hydrogen peroxide and catalyst which demonstrate that RB5 shows high catalytic degradation at high concentrations of hydrogen peroxide and catalyst.

scholarly journals Mineral chemistry of In-bearing minerals in the Santa Fe mining district, Bolivia

2018 ◽  
Vol 45 (3) ◽  
pp. 410 ◽  
Author(s):  
Abigail Jiménez-Franco ◽  
Pura Alfonso ◽  
Carles Canet ◽  
Juan Elvys Trujillo
Keyword(s):  
Mineral Chemistry ◽  
Point Of View ◽  
Igneous Rocks ◽  
Mining District ◽  
Critical Element ◽  
Santa Fe ◽  
Economic Point ◽  
Quartz Veins ◽  
Mineral Phases ◽  
High Concentrations

The Santa Fe mining district is located in the Central Andean tin belt of Bolivia and contains several Sn-Zn-Pb-Ag deposits. From the economic point of view, the most important deposits of the district are Japo, Santa Fe and Morococala. Beyond the traditional metal commodities, the Central Andean Tin Belt could become an exploration target for indium, owing to the potential of the ore-bearing paragenesis with high concentrations of this technology-critical element. In the Santa Fe mining district, the ore occurs as two main types: (a) Sn-rich cassiterite-quartz veins, and (b) Zn-Pb-Ag veins with sphalerite, galena and stannite mineral phases. The In content in igneous rocks is between 1.5 and 2.5 ppm, whereas in the ore concentrate it attains up to 200 ppm. The 1,000×In/Zn ratio in concentrate ranges from 25 up to 4,000. Exceptionally high In values were found in sakuraiite from Morococala deposit (2.03 wt%). Sakuraiite in this deposit shows evidences for a link between stannite and kësterite trend of solid solutions. There is a noteworthy exploration potential for strategic metals in this district and even in similar deposits elsewhere in the Central Andean tin belt.

Vacancy and oxygen behavior in carbon highly doped silicon

2001 ◽  
Vol 669 ◽  
Author(s):  
Pierre Lavéant ◽  
Peter Werner ◽  
Norbert Engler ◽  
Ulrich Goesele
Keyword(s):  
Point Defects ◽  
Bipolar Transistors ◽  
Carbon Doping ◽  
High Carbon ◽  
High Oxygen Concentration ◽  
High Carbon Concentration ◽  
Carbon Precipitation ◽  
High Concentrations ◽  
Co Precipitation ◽  
Silicon Based

ABSTRACTCarbon doping of silicon has gained interest since in high concentrations, carbon can reduce oreven suppress undesirable diffusion of the base dopant boron in silicon-based bipolar transistors. This behavior can only be understood in taking into account the silicon point defects i.e. vacancies and self-interstitials. In this work, we observe the oversaturation of vacancies produced by a high carbon concentration duringannealing. Experiments with a vacancy diffusing dopant, Antimony, are shown and prove this effect: in a carbon rich sample, the antimony diffusion is enhanced about 8 times compared to samples with a much lower carbonconcentration. We also investigate the carbon co-precipitation with oxygen. The carbon precipitation, asSiC, is facilitated with a high oxygen concentration. We explain this affinity by an exchange of point defects and a volume compensation. Finally, we show the precipitation of oxygen in relation to the vacancy oversaturation at 900°C.

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